Breathing apparatus for use in emergency situations have previously been disclosed in the prior art. By way of example, such devices are disclosed in the following U.S. Pat. Nos.: 4,164,218; 4,221,216; 4,362,153; 4,409,978; 4,440,163; and 4,696,295. These prior patents disclose devices of varying complexity, but all have inherent problems or disadvantages that are overcome through use of the present invention.
Most of the emergency breathing devices disclosed in the prior art employ hoods or masks that are to be placed over the head and face of the user prior to use. Others are so heavy or cumbersome that they must be tied around the body of the user or else supported by one or both hands during use. Still others employ exhaust valves or filters for the purpose of venting or purifying exhaled gas.
Notwithstanding the capabilities of some of the more elaborate emergency breathing systems that have previously been disclosed or are presently being marketed, there remains a need for a very lightweight, portable, emergency breathing apparatus that is economical to manufacture and deploy; that can be placed in virtually instantaneous use with little or no prior training or instruction; that can be entirely supported from the mouth of the user, thereby freeing both hands for other purposes in emergency situations; and that will provide an emergency source of oxygen-containing gas for an interval of a few minutes in order to permit the user to extricate himself or herself from the emergency situation.